A respiratory mask is generally comprised of a frame, sealing cushion, air delivery elbow, adjustable forehead support having one or more forehead pads, and headgear.
The forehead support serves to stabilize the mask on the patient's face and ensures that the cushion locates correctly on the patient's facial profile. The forehead support generally anchors the frame in such a way as to allow the frame and cushion to pivot around the forehead pad so that the cushion does not collapse under headgear tension. This maintains the cushion in sealing abutment with the patient's face.
The purpose of the headgear is to stabilize the mask, including the forehead support and cushion, at the chosen location on the patient's face. This helps to reduce leak around the cushion.
It is generally preferable that areas of mask contact with the patient's face feel soft to the patient and distribute headgear tension forces over an area.
A typical forehead support comprises a generally T-shaped or I-shaped rigid or semi-rigid component having a pair of forehead pads attached thereto, and having one or more hooks, slots or clip receptacles adapted to engage with headgear straps. See U.S. Pat. Nos. 6,119,693, 6,532,961, and 7,216,647, published PCT Application No. WO 2006/074517, and U.S. Provisional Application No. 60/858,694.
Forehead pads are typically cut from foam, molded or extruded in silicone, or constructed from a soft, comfortable material in contrast to the more rigid material of the forehead support, which is often molded from a polycarbonate material.
Other forms of mask may include a semi-rigid stabilizing structure having a fabric and foam layer stitched or otherwise attached thereto. See published PCT Application No. WO 2003/090827.